bool = cregion:IsNull()
True if the region is NULL, i.e. invalid. If functions
that allocate regions fail, they might not throw an error but simply set the
region to NULL. You can use this function to check if region allocation has
failed in which case the region will be NULL.
Also, certain getter functions can return a NULL object in case the object
doesn't exist. You can use this function to check if a getter function returned
a NULL handle.
True if the region is NULL, otherwise False